Special places archive

Lighthouses for aeroplanes

Concrete arrows and the US airmail beacon system is a post on the Sometimes interesting blog describing a system that has left strange concrete arrows across the American landscape. In con­trast to marine lighthouses which have stood for centuries and are still lit every night, these aerial navigation aids had a short service life.

In 1924 the US Postal Service began to build a network of giant concrete arrows which pilots could see from the air during day­light, with flashing lights on towers for night navigation. By 1933 radio direction-finding systems had been developed, and the beacon system became obsolete.